[PATCH v3 09/20] ceph_d_revalidate(): use stable parent inode passed by caller

Al Viro
2025-01-23T01:46:45Z

No need to mess with the boilerplate for obtaining what we already
have. Note that ceph is one of the "will want a path from filesystem
root if we want to talk to server" cases, so the name of the last
component is of little use - it is passed to fscrypt_d_revalidate()
and it's used to deal with (also crypt-related) case in request
marshalling, when encrypted name turns out to be too long. The former
is not a problem, but the latter is racy; that part will be handled
in the next commit.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
fs/ceph/dir.c | 22 ++++------------------
1 file changed, 4 insertions(+), 18 deletions(-)

diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index c4c71c24221b..dc5f55bebad7 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -1940,30 +1940,19 @@ static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry,
/*
* Check if cached dentry can be trusted.
*/
-static int ceph_d_revalidate(struct inode *parent_dir, const struct qstr *name,
+static int ceph_d_revalidate(struct inode *dir, const struct qstr *name,
struct dentry *dentry, unsigned int flags)
{
struct ceph_mds_client *mdsc = ceph_sb_to_fs_client(dentry->d_sb)->mdsc;
struct ceph_client *cl = mdsc->fsc->client;
int valid = 0;
- struct dentry *parent;
- struct inode *dir, *inode;
+ struct inode *inode;

- valid = fscrypt_d_revalidate(parent_dir, name, dentry, flags);
+ valid = fscrypt_d_revalidate(dir, name, dentry, flags);
if (valid <= 0)
return valid;

- if (flags & LOOKUP_RCU) {
- parent = READ_ONCE(dentry->d_parent);
- dir = d_inode_rcu(parent);
- if (!dir)
- return -ECHILD;
- inode = d_inode_rcu(dentry);
- } else {
- parent = dget_parent(dentry);
- dir = d_inode(parent);
- inode = d_inode(dentry);
- }
+ inode = d_inode_rcu(dentry);

doutc(cl, "%p '%pd' inode %p offset 0x%llx nokey %d\n",
dentry, dentry, inode, ceph_dentry(dentry)->offset,
@@ -2039,9 +2028,6 @@ static int ceph_d_revalidate(struct inode *parent_dir, const struct qstr *name,
doutc(cl, "%p '%pd' %s\n", dentry, dentry, valid ? "valid" : "invalid");
if (!valid)
ceph_dir_clear_complete(dir);
-
- if (!(flags & LOOKUP_RCU))
- dput(parent);
return valid;
}

--
2.39.5